Not so fast. There is no fossil evidence for a single trunk. As Stephen Jay Gould explains, the evidence points in the opposite direction:
The history of most fossil species include two features particularly inconsistent with gradualism:
1) Stasis - most species exhibit no directional change during their tenure on earth. They appear in the fossil record looking much the same as when they disappear; morphological change is usually limited and directionless;
2) Sudden appearance - in any local area, a species does not arise gradually by the steady transformation of its ancestors; it appears all at once and ‘fully formed’.
Gould, S.J. (1977)
“Evolution’s Erratic Pace”
Natural History, vol. 86, May
They would remain in their form since they are fully evolved as such. Every species we see on earth now is fully evolved and would not exhibit directional change. If something evolves from that it would be a new species.
1) Stasis - most species exhibit no directional change during their tenure on earth. They appear in the fossil record looking much the same as when they disappear; morphological change is usually limited and directionless;
2) Sudden appearance - in any local area, a species does not arise gradually by the steady transformation of its ancestors; it appears all at once and fully formed.
When did God give us the English Bulldog?
When did God give us the French Poodle?
When did God give us the Boston Terrier?